Stabilization of 2-thenyl chloride



Patented Dec. 21, 1948 2,457,08l I UNliTED PATENTIOFFICE STABILIZATION OF 2-THEN'YL CHLORIDE FerdinandB-MZienty, St. Louis, Mo., assignor to Monsanto fihemlcal Company, St. Louis, Mo., a. corporation of Delaware e t wormin Application October 18, 194.6,

. 'SeflalNo. 704,289

This invention relates to the stabilization of Z-thenyl chloride and more particularly to a novel. composition; comprising z-thenyl chloride and: a: stabilizer thereionc 2-thenylL chloride is potentially a. very useful intermediate because of its great reactivity'and resemblance in certain respects to benzyl chloride. However, unlike benzyl chloride, 2-theny1 chloride is relatively unstable at normal and subnormal temperatures, and storage of the material at room temperature or at lower temperature. is unieasible because the material resimifies very readily to form. a, black resin. Eventhe storage of 2-thenyl chloride at. C1. or below does: not avoictthis: decompositiom Moreover, Z-thenyl chloride is highly reactive and. combines readily with a large; number oi basic substances; such as aniline, methyl aniline, dimethyl anilins trie methyl amine; pyridine; andother' amines, thereby depicting the Z-thenyl chloride; and: rendering it unavailable for: desired. reactimm.

One of the objects of the present, invention is to provide a novel composition comprising 2- thenyl chloride having, incorporated therein certain amines which stabilize the Z-thenyl chloride substantially without depleting the activity of the Z-thenyl chloride.

1 Another object isto provide a novel methodfor stabilizing 2-thenyl. chloride. a 1 H A Furtherobiects will become apparent: incur the following. description and examples. 1 According to:- the present invention, generally stated, acomposition exhibiting; markedistability at normal andsubnormaltemperatures and hay:- ingv the full activity of freshly prepared; Z-thenyl chloride isg provided by incorporating; with 2 thenyl chloride. 0.5- %s, Qrevenh nor'e, tor ex.- ample -15%, and desirably 1--2%' hywei'ghtj. of an amine selected from the group consisting of pyrrolidones of the. formula type: CH-CH2 o= H-R imwhicn R. re resents a radibat selected; from the group consisting of hydrogen: and: alkyi moi. cal's containing from 1 to: 3 carbon atoms,- mo R1 represents a radical selected. from: the groupcoirsisting of alkyl radicals containing: at; least 1 2 carbonatoms; cycl'oalkyr radicals containing at least 51 carbon atoms, and aralkyl radicals;

Inorder to provide maxi-mumvstabillty' in the composition of th present invention; it i s deisirable to eliminate from the 2-thenyl chloride substantially all of-zthe free acidity which may be present therein and also to render the material substantially anhydrous, for example, to the extent of containing less than 0.5% moisture and desirably less: than. 0.2% moisture. This? may be 16 claims (Cl. 260 -329) z pyrrolidon'e,

' pyrrolidone,

accomplished, for example; by washing z-the'nyl chloride with a cold aqueous solution contain" ing 5% by weight of sodium bicarbonate, thereafter washing the 2l-thenyl chloride. with cold water, for example, ice water, andrecovering. the z tlienyl chloride. in. substantially anhydrous form. by fractional-distillation under reduced pressure. 1 To the. fractionally distilled :Z-thenyl chloride added an amine of. the aiorescribed type in: amounts as' hereinbeiore: described.

The 2-thenyl chloride composition thus obtained has been found to be stable for more than 9 months at 5C., more: than 3 months at C., and. as long as 3 months at 42C. Moreover,the Z-thenyl chloride composition thus prepared has been: found. to possess substantially the reactiyity of freshly distilled. 2 -theny1 chloride and may be employed in chemical reactions in substantially the stoichiometric amounts base upon the con tent of Z-thenyl chloride employed in the prepa ration; of, the composition of the present. inven- Illustrativeofi the amines suitable for the preparation of the novel composition. of. the. pres ent invention are; 1-dodecyl-2-pyrrolidone, 1- dodecyl-2-methyl-5 pyrrolidone, 1-benzyl-2-pyrrolirtone-,.1 oyolohexyl 2 pyrrolido-n-e l-cycl'opentyl-'2.- p'yrrolidone; 1" naphth-yl'p-Z -pyrrolidones, Isheptadeoyl-hpyrrolidone; I-octad'ecyll-cyclohexyl=-2-propyl 5-pyrrolidome l;-berizyl 2 ethyl5-pyrro1idone,. 1-cyclohexyl-cyclbhexyl z methyL- 5 pyrrolidone, 1- benzyls2i-nrethylw5 pyrrolidone', 1-.-heptadecycl- 2: methyl. 5 pyrrolidone; kdodecyl -2-ethylfili-dbdecyl-m-isopropyl 5 pyrrolidone.

The following examples will. serve to illustrate the novel. compositions: of the present. invention and: the preparation thereof. These examples are to be construed merely as illustrative and as limiting the present invention except as defined in the appende'e clai-ms.

. Bram le. 1'

A quantity of Z-thenyl chloride was Washed with cold: 5% sodium bicarbonate: solution to removeireeacidity The washed material. was then washed: with ice: water and fractionally distilled under reduced pressure: To the acid fr ee, sub stantialigt anhydrous Z-thenyl: chloridethllSvQbftamed was added. 1% by weight. of 1-dodecy1--2- pyrroiidone; The composition thus. obtained was stored for more than. S mon-tbs awe-45 Ct, dar Which-1 time? only a light brown: coloration developed in the; composition. In coi'itra-st,v an unstabilized quantity of; acid-free, substantially animydmous; 2-thenyt cli-Ioricle stored at. all-45 G. tuimeddark. within 2-3- days. and decomposed-to a1 blawfresirrirr ap'eriod at 7-14" days; E0: addi tionalquantitiesiot freshly: distiiledg. acid-tree anhydrous Z-thenyl chloride were added respectively 0.5%, 2%, and by weight of 1- dodecyl-Z-pyrrolidone. In each instance, a composition stable at temperatures ranging from 042 C. for periods of time ranging from more than 3 months to more than 9 months were obtained.

Example II To respective portions of a quantity of freshly distilled acid-free substantially anhydrous 2- thenyl chloride were added 0.5%, 1%, 2%, and 5% by weight of a mixture of 1-dodecyl-2-methyl-5- pyrrolidone. found to be stable at 5 C. for more than 9 months with substantially no tendency toward resinification.

' Example III To respective portions of freshly distilled acidfree Z-thenyl chloride containing 0.1% of moisture, were added 0.5%, 1%, 2%, and 5% by weight of a mixture of 1:cyclohexyl-Z-methyl-5-pyrrolidone. After a period of more than 3 months, only a light brown color had developed in the composition and there was no evidence of resinification of the 2-thenyl chloride content of the composition.

Example IV Example V For the purpose of the following preparation, a quantity of Z-thenyl chloride was employed which had been stored after preparation for 3 days at 5" 0.. This material had developed some free acidity. To a quantity of this material was added 1% by weight of 1-dodecyl-2-pyrrolidone. The resulting composition was found to possess approximately or less of the stability of a corresponding composition prepared from freshly distilled, acid-washed, substantially anhydrous 2- thenyl chloride and 1%of l-dodecyl-2-pyrroli- .done. This stability was ascertained by the appearance of the sample over several weeks time in storage at 5 C. It has been found feasible to utilize a composition of this type in those instances in which'a stock of Z-thenyl chloride is to be employed in chemical reactions within a. few weeks of the time at which the Z-thenyl chloride is prepared.

The novel compositions of the present invention, particularly when prepared from freshly distilled substantially anhydrous 2-thenyl chloride containing a trace or less of free acidity, have been found to be entirely satisfactory foruse in chemical reactions without distilling the composition prior to such use. With the possible exception of a few instances in which the presence of the stabilizer might be considered undesirable in a reaction mixture involving 2-thenyl chloride, it is unnecessary to fractionate the composition of the present invention prior to its use in reactions. If such fractionation is deemed desirable, it has been found that there is substantially no evidence of a high boiling residue'in thedistilla- The resulting compositions were.-

tion flask after the distillation of any of the compositionsof the present invention. This is additional evidence of the substantial absence of any tendency toward resinification of the novel compositions of the present invention.

I Example VI .A quantity-of Z-thenyl chloride was washed with a cold 5% aqueous solution of sodium bicarbonate and then with cold water until substan- V tially neutral. The material was then dried over calcium chloride. To the dried, acid-free Z-thenyl chloride was added 2% of l-dodecyl-2-pyrrolidone. The resulting composition was found to be substantially free from resinification at the end of 9 months of storage at 5C. v

Iclaimn I. A stablecomposition consisting of 2-thenyl chloride and a small portion of an amine selected from the group consisting of pyrrolidonesof the formula type:

our-om N in in which R'represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbonatoms, and R1 represents a radical selected from the group consisting of alkyl'radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkylradicals.

2. A stable composition consisting of 2-thenyl chloride and atleast 0.5% of an amine selected from the group consisting of pyrrolidones of the formulatyper in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least5 carbon'atoms, and aralkyl radicals. I

3.1; stable composition consisting of 2-thenyl chloride and 0.5-5% of an amine selected from the group consisting of pyrrolidones of the formulatype:

in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 12 to 3 carbon atoms, and R1 represents a radicalselected from the group consisting of alkyl radicals containing at least 12- carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

LA-stable compositionconsisting of 2-thenyl chlorideand 05-10% of a amine selected from the group '.consisting of pyrrolidones' of the in which R' i'epr'esents' a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consist-.- ing of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals contains at least 5 carbon atoms, and aralkyl radicals.

5. A stable composition consisting of 2-thenyl chloride and 1-2% of an amine selected from the group consisting of pyrrolidones of the formula type:

R1 in which R represents a radical selected from the group consistin of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R 1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

6. A stable composition consisting of 2-theny1 chloride and at least 0.5% of l-dodecyl-2-pyrrolidone.

7. A stable composition consistingof 2-thenyl chloride and 1-2% of l-dodecyl-2-pyrrolidone.

8. A stable composition consisting of 2-thenyl chloride and at least 0.5% of 1-dodecy1-2-methylpyrrolidone.

9. A stable composition consisting of Z-thenyl chloride and at least 0.5% of 1-cyclohexyl-2- methyl-5-pyrrolidone.

10. A process of stabilizing 2-thenyl chloride Q comprising incorporating therein a small portion of an amine selected from the group consisting of pyrrolidones of the formula type:

CHz-CH: o=d OH-R in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

11. A process of stabilizing Z-thenyl chloride comprising incorporating therein at least 0.5% of an amine selected from the group consisting of pyrrolidones of the formula type:

in which R represents a radical selected from the comprising incorporating in substantially neutral,

in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

13. A process of stabilizing 2-thenyl chloride comprising incorporating in substantially neutral, freshly distilled 2-thenyl chloride distillate at least 0.5% of 1 -dodecyl-2-pyrrolidone.

14. A process of stabilizing 2-theny1 chloride comprising adding to substantially neutral and salt-free, freshly distilled 2-thenyl chloride 2. small quantity of an amine selected from the group consisting of pyrrolidones of the formula type:

CHr-OHz GH-R in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

15. A process of stabilizing 2-theny1 chloride comprising adding to substantially neutral and salt-free, anhydrous 2-thenyl chloride at least 0.5% of an amine selected from the group consisting of pyrrolidones of the formula type:

in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

16. A process of stabilizing 2-thenyl chloride comprising adding to substantially neutral and salt-free, freshly distilled 2-thenyl chloride at least 0.5% of an amine selected from the group consisting of pyrrolidones of the formula type:

in which R represents a radical selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 3 carbon atoms, and R1 represents a radical selected from the group consisting of alkyl radicals containing at least 12 carbon atoms, cycloalkyl radicals containing at least 5 carbon atoms, and aralkyl radicals.

FERDINAND B. ZIENTY.

REFERENCES CITED The following references are of record in the file of this patent:

Chemical Abstracts, 20, 390 (1926). 

